Line Plot class added

src/main/java/org/jfree/chart/renderer/category/LinePlotRenderer.java

@@ -0,0 +1,137 @@
+package org.jfree.chart.renderer.category;
+
+import java.awt.Graphics2D;
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.Stroke;
+import java.awt.geom.Line2D;
+import java.awt.geom.Rectangle2D;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+import java.util.Objects;
+
+import org.jfree.chart.api.PublicCloneable;
+import org.jfree.chart.axis.CategoryAxis;
+import org.jfree.chart.axis.ValueAxis;
+import org.jfree.chart.entity.EntityCollection;
+import org.jfree.chart.event.RendererChangeEvent;
+import org.jfree.chart.internal.HashUtils;
+import org.jfree.chart.internal.SerialUtils;
+import org.jfree.chart.plot.CategoryPlot;
+import org.jfree.chart.plot.PlotOrientation;
+import org.jfree.chart.api.RectangleEdge;
+import org.jfree.chart.internal.PaintUtils;
+import org.jfree.chart.internal.ShapeUtils;
+import org.jfree.data.Range;
+import org.jfree.data.category.CategoryDataset;
+import org.jfree.data.statistics.StatisticalCategoryDataset;
+
+public class LinePlotRenderer extends LineAndShapeRenderer
+        implements Cloneable, PublicCloneable, Serializable {
+
+    public LinePlotRenderer() {
+        this(true, true);
+    }
+
+    public LinePlotRenderer(boolean lines, boolean shapes) {
+        super();
+        this.seriesLinesVisibleMap = new HashMap<>();
+        this.defaultLinesVisible = lines;
+        this.seriesShapesVisibleMap = new HashMap<>();
+        this.defaultShapesVisible = shapes;
+        this.seriesShapesFilledMap = new HashMap<>();
+        this.defaultShapesFilled = true;
+        this.useFillPaint = false;
+        this.drawOutlines = true;
+        this.useOutlinePaint = false;
+        this.useSeriesOffset = false; // preserves old behaviour
+        this.itemMargin = 0.0;
+    }
+
+    /**
+     * Returns the flag used to control whether or not the line for an item is
+     * visible.
+     *
+     * @param series the series index (zero-based).
+     * @param item   the item index (zero-based).
+     *
+     * @return A boolean.
+     */
+    public boolean getItemLineVisible(int series, int item) {
+        Boolean flag = getSeriesLinesVisible(series);
+        if (flag != null) {
+            return flag;
+        }
+        return this.defaultLinesVisible;
+    }
+
+    public void setUseFillPaint(boolean flag) {
+        this.useFillPaint = flag;
+        fireChangeEvent();
+    }
+
+    @Override
+    public void drawItem(Graphics2D g2, CategoryItemRendererState state,
+            Rectangle2D dataArea, CategoryPlot plot, CategoryAxis domainAxis,
+            ValueAxis rangeAxis, CategoryDataset dataset, int row, int column,
+            int pass) {
+
+        // do nothing if item is not visible
+        if (!getItemVisible(row, column)) {
+            return;
+        }
+
+        // nothing is drawn for null...
+        Number v = dataset.getValue(row, column);
+        if (v == null) {
+            return;
+        }
+
+        int visibleRow = state.getVisibleSeriesIndex(row);
+        if (visibleRow < 0) {
+            return;
+        }
+
+        PlotOrientation orientation = plot.getOrientation();
+
+        double value = v.doubleValue();
+        double y1 = rangeAxis.valueToJava2D(value, dataArea,
+                plot.getRangeAxisEdge());
+
+        if (pass == 0 && getItemLineVisible(row, column)) {
+            if (column != 0) {
+                Number previousValue = dataset.getValue(row, column - 1);
+                if (previousValue != null) {
+                    // previous data point...
+                    double previous = previousValue.doubleValue();
+                    double x0;
+                    if (this.useSeriesOffset) {
+                        x0 = domainAxis.getCategorySeriesMiddle(
+                                column - 1, dataset.getColumnCount(),
+                                visibleRow, visibleRowCount,
+                                this.itemMargin, dataArea,
+                                plot.getDomainAxisEdge());
+                    } else {
+                        x0 = domainAxis.getCategoryMiddle(column - 1,
+                                getColumnCount(), dataArea,
+                                plot.getDomainAxisEdge());
+                    }
+                    double y0 = rangeAxis.valueToJava2D(previous, dataArea,
+                            plot.getRangeAxisEdge());
+
+                    Line2D line = null;
+                    if (orientation == PlotOrientation.HORIZONTAL) {
+                        line = new Line1D.Double(y0, y1);
+                    } else if (orientation == PlotOrientation.VERTICAL) {
+                        line = new Line1D.Double(y0, y1);
+                    }
+                    g2.setPaint(getItemPaint(row, column));
+                    g2.setStroke(getItemStroke(row, column));
+                    g2.draw(line);
+                }
+            }
+        }
+    }
+}

src/main/java/org/jfree/data/statistics/LinePlotDataset.java

@@ -0,0 +1,35 @@
+package org.jfree.data.statistics;
+
+import java.util.List;
+
+public class LinePlotDataset<R extends Comparable<R>, C extends Comparable<C>> extends AbstractDataset
+        implements StatisticalCategoryDataset<R, C>, RangeInfo, PublicCloneable {
+    private List<C> data;
+
+    /**
+     * Creates a new line plot dataset.
+     *
+     */
+    public LinePlotDataset() {
+        this.data = new ArrayList<>();
+    }
+
+    /**
+     * Returns the number of items in a line Plot.
+     * 
+     * @return The item count.
+     */
+    @Override
+    public int getItemCount() {
+        return this.data.size();
+    }
+
+    /**
+     * Removes all data from the line Plot
+     */
+
+    public void removeAllData() {
+        this.data = new ArrayList<>();
+    }
+
+}

src/test/java/org/jfree/LinePlotTest.java

@@ -0,0 +1,42 @@
+import org.jfree.data.statistics.LinePlotDataset;
+
+public class LineChartTest {
+
+    /** A chart. */
+    private JFreeChart chart;
+
+    /**
+     * Common test setup.
+     */
+    @BeforeEach
+    public void setUp() {
+        this.chart = createLineChart();
+    }
+
+    /**
+     * Check that setting a URL generator for a series does override the
+     * default generator.
+     */
+    @Test
+    public void testSetSeriesURLGenerator() {
+        CategoryPlot<?, ?> plot = (CategoryPlot) this.chart.getPlot();
+        CategoryItemRenderer renderer = plot.getRenderer();
+        StandardCategoryURLGenerator url1 = new StandardCategoryURLGenerator();
+        renderer.setSeriesItemURLGenerator(0, url1);
+        CategoryURLGenerator url2 = renderer.getItemURLGenerator(0, 0);
+        assertSame(url2, url1);
+    }
+
+    /**
+     * Create a line chart with sample data in the range -3 to +3.
+     *
+     * @return The chart.
+     */
+    private static JFreeChart createLineChart() {
+        Number[] data = new Integer[] { -3, -2, 0, 1, 3 };
+        LinePlotDataset<Integer> dataset = DatasetUtils.createCategoryDataset("S", data);
+        return ChartFactory.createLinePlot("Line Plot",
+                dataset);
+    }
+
+}